Editor in Preferenced did not scale on Ubuntu

[mdk]

What steps will reproduce the problem?

1. Need Ubuntu 20.04 and HiDPI Monitor
2. Konfigure Ubuntu to use Scale factor 2.0:

3. Konfigure in JOSM Advanced Preferences all "Scale" Properties to "2.0" and restart

see file scale2.0.xml

3. Go to JOSM Advanced Preferences and edit a value.

What is the expected result?

The Editor (and the hover text) has the same size as the normal text in the grid.

What happens instead?

Both texts are not scaled (like many other texts in JOSM)

Please provide any additional information below. Attach a screenshot if possible.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-09-18 21:11:43 +0200 (Fri, 18 Sep 2020)
Revision:17038
Build-Date:2020-09-19 01:30:48
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (17038 en) Linux Ubuntu 20.04.1 LTS
Memory Usage: 329 MB / 1980 MB (98 MB allocated, but free)
Java version: 14.0.1+7-Ubuntu-1ubuntu1, Private Build, OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 3840x2160 (scaling 1.0x1.0)
Maximum Screen Size: 3840x2160
Best cursor sizes: 16x16 -> 16x16, 32x32 -> 32x32
Desktop environment: ubuntu:GNOME
Java ATK Wrapper package: libatk-wrapper-java:all-0.37.1-1
libcommons-compress-java: libcommons-compress-java:all-1.19-1
libcommons-logging-java: libcommons-logging-java:all-1.2-2
fonts-noto: fonts-noto:-
VM arguments: [--add-modules=java.scripting,java.sql, -Djosm.restart=true, -Djosm.dir.name=JOSM-latest, -Djava.net.useSystemProxies=true]

Plugins:
+ ColumbusCSV (35405)
+ FastDraw (35499)
+ HouseNumberTaggingTool (35508)
+ OpeningHoursEditor (35414)
+ RoadSigns (35510)
+ SimplifyArea (35405)
+ buildings_tools (35500)
+ contourmerge (v0.1.6)
+ imagery-xml-bounds (35546)
+ imagery_offset_db (35405)
+ pbf (35446)
+ poly (35248)
+ public_transport (35405)
+ reltoolbox (35529)
+ reverter (35499)
+ terracer (35499)
+ turnrestrictions (35515)
+ utilsplugin2 (35487)
+ wikipedia (1.1.4)

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/OneClick&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/LaneAttributes&preset&zip=1

Map paint styles:
+ https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Styles/Maxspeed&style&zip=1